Program to print hollow rectangle or square star patterns

Hollow rectangle star pattern :

The task is print below hollow pattern of given dimension. 

********************
*                  *
*                  *
*                  *
*                  *
********************

Explanation:

• Input number of rows and columns.
• For rows of rectangle run the outer loop from 1 to rows. 
  

for (i = 1; i < = rows; i++)

• For column of rectangle run the inner loop from 1 to columns. 
  

for (j = 1; j < = columns; j++)

• Print star for first or last row or for first or last column, otherwise print blank space.
• After printing all columns of a row, print new line after inner loop.

C++

// C++ code for hollow rectangle
#include <bits/stdc++.h>
using namespace std;

// Function to print hollow rectangle
void print_rectangle(int n, int m)
{
    int i, j;
    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= m; j++)
        {
            if (i == 1 || i == n ||
                j == 1 || j == m)
                cout << "*";
            else
                cout << " ";
        }
        cout << endl;
    }

}

// Driver Code
int main()
{
    int rows = 6, columns = 20;
    print_rectangle(rows, columns);
    return 0;
}

// This code is contributed
// by rathbhupendra

C

// C code for hollow rectangle
#include <stdio.h>

// Function to print hollow rectangle
void print_rectangle(int n, int m)
{
    int i, j;
    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= m; j++)
        {
            if (i==1 || i==n || j==1 || j==m)
                printf("*");
            else
                printf(" ");
        }
        printf("\n");
    }

}

// Driver program for above function
int main()
{
    int rows = 6, columns = 20;
    print_rectangle(rows, columns);
    return 0;
}

Java

// JAVA code for hollow rectangle
import java.io.*;

class GFG {

    // Function to print hollow rectangle
    static void print_rectangle(int n, int m)
    {
        int i, j;
        for (i = 1; i <= n; i++)
        {
            for (j = 1; j <= m; j++)
            {
                if (i == 1 || i == n ||
                    j == 1 || j == m)
                    System.out.print("*");
                else
                    System.out.print(" ");
            }
            System.out.println();
        }

    }

    // Driver program for above function
    public static void main(String args[])
    {
        int rows = 6, columns = 20;
        print_rectangle(rows, columns);
    }
}

/*This code is contributed by Nikita Tiwari.*/

Python3

# Python 3 code for hollow rectangle

# Function to print hollow rectangle
def print_rectangle(n, m) :

    for i in range(1, n+1) :
        for j in range(1, m+1) :
            if (i == 1 or i == n or
                j == 1 or j == m) :
                print("*", end="")
            else :
                print(" ", end="")

        print()


# Driver program for above function
rows = 6
columns = 20
print_rectangle(rows, columns)


# This code is contributed by Nikita Tiwari.

C#

using System;
public class GFG
{

  // Function to print hollow rectangle
  static void print_rectangle(int n, int m)
  {
    int i, j;
    for (i = 1; i <= n; i++)
    {
      for (j = 1; j <= m; j++)
      {
        if (i == 1 || i == n ||
            j == 1 || j == m)
          Console.Write("*");
        else
          Console.Write(" ");
      }
      Console.WriteLine();
    }

  }

  // Driver program for above function
  public static void Main()
  {
    int rows = 6, columns = 20;
    print_rectangle(rows, columns);
  }
}

// This code is contributed by ksrikanth0498.

PHP

<?php
// PHP code for hollow rectangle

// Function to print hollow rectangle
function print_rectangle($n, $m)
{
    $i;
    $j;
    for ($i = 1; $i <= $n; $i++)
    {
        for ($j = 1; $j <= $m; $j++)
        {
            if ($i == 1 || $i == $n ||
                $j == 1 || $j == $m)
                echo("*");
            else
                echo(" ");
        }
        echo("\n");
    }

}

    // Driver Code
    $rows = 6;
    $columns = 20;
    print_rectangle($rows, $columns);

// This code is contributed by nitin mittal
?>

Javascript

<script>
      // JavaScript code for hollow rectangle
      // Function to print hollow rectangle
      function print_rectangle(n, m)
      {
        var i, j;
        for (i = 1; i <= n; i++)
        {
          for (j = 1; j <= m; j++)
          {
            if (i == 1 || i == n || j == 1 || j == m)
                 document.write("*");
            else
                document.write("  ");
          }
          document.write("<br>");
        }
      }

      // Driver Code
      var rows = 6,
        columns = 20;
      print_rectangle(rows, columns);

      // This code is contributed by rdtank.
    </script>

Output: 

********************
*                  *
*                  *
*                  *
*                  *
********************

Time Complexity: O(m * n), where m and n represents the given inputs.
Auxiliary Space: O(1), no extra space is required, so it is a constant.

Hollow square star pattern :

********
*      *
*      *
*      *
*      *
*      *
*      *
********

Explanation:

• Input number of rows.
• For rows, an outer loop from 1 to N.
• For columns, an inner loop from 1 to N
• Inside inner loop print star for first and last row or for first and last column. Which is print star 
  

 if i == 1 or i == N or j == 1 or j == N

• otherwise print space.
• After printing all columns of a row, print a blank line after inner loop. 
  

C++

// C++ code for hollow squares
#include <bits/stdc++.h>
using namespace std;

// Function to print hollow square
void print_square(int n)
{
    int i, j;

    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= n; j++)
        {
            if (i==1 || i==n || j==1 || j==n)
                cout << "*";
            else
                cout << " ";
        }
        cout << "\n";
    }

}

// Driver code for above function
int main()
{
    int rows = 8;
    print_square(rows);
    return 0;
}

// This code is contributed by Code_Mech

C

// C code for hollow squares
#include <stdio.h>

// Function to print hollow square
void print_square(int n)
{
    int i, j;

    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= n; j++)
        {
            if (i==1 || i==n || j==1 || j==n)
                printf("*");
            else
                printf(" ");
        }
        printf("\n");
    }

}

// Driver code for above function
int main()
{
    int rows = 8;
    print_square(rows);
    return 0;
}

Java

// JAVA code for hollow squares
import java.io.*;

class GFG {

    // Function to print hollow square
    static void print_square(int n)
    {
        int i, j;

        for (i = 1; i <= n; i++)
        {
            for (j = 1; j <= n; j++)
            {
                if (i == 1 || i == n ||
                    j == 1 || j == n)
                    System.out.print("*");
                else
                    System.out.print(" ");
            }
            System.out.println();
        }

    }

    // Driver code for above function
    public static void main(String args[])
    {
        int rows = 8;
        print_square(rows);
    }
}

/*This code is contributed by Nikita Tiwari.*/

Python3

# Python 3 code for hollow squares

# Function to print hollow square
def print_square(n) :

    for i in range(1, n+1) :
        for j in range(1, n+1) :
            if (i == 1 or i == n or
                j == 1 or j == n) :
                print("*", end = "")
            else :
                print(" ", end = "")

        print()



# Driver code for above function
rows = 8
print_square(rows)

# This code is contributed by Nikita Tiwari.

C#

// C# program to print hollow square
// star pattern with diagonal
using System;

class GFG {

    // Function to print hollow square with
    // primary and secondary diagonal
    static void print_squaredi(int n)
    {
        int i, j;
        for (i = 1; i <= n; i++)
        {
            for (j = 1; j <= n; j++)
            {
                if (i == 1 || i == n ||
                    j == 1 || j == n ||
                    i == j || j == (n - i + 1))
                    Console.Write("*");
                else
                Console.Write(" ");
            }
            Console.WriteLine();
        }

    }

    // Driver code
    public static void Main()
    {
        int rows = 8;
        print_squaredi(rows);
    }
}

// This code is contributed by Nitin Mittal.

PHP

<?php
// PHP program to print hollow square
// star pattern with diagonal

// Function to print hollow square with
// primary and secondary diagonal
function print_squaredi($n)
{
    $i;
    $j;
    for($i = 1; $i <= $n; $i++)
    {
        for ($j = 1; $j <= $n; $j++)
        {
            if($i == 1 or $i == $n or $j == 1 ||
               $j == $n or $i == $j or $j == ($n -
                                          $i + 1))
                printf("*");
            else
                echo " ";
        }
        echo "\n";
    }

}

    // Driver Code
    $rows = 8;
    print_squaredi($rows);

// This code is contributed by anuj_67.
?>

Javascript

Javascript
    // Function to print hollow square
    function print_square(int n)
    {
        var i, j;

        for (i = 1; i <= n; i++)
        {
            for (j = 1; j <= n; j++)
            {
                if (i == 1 || i == n ||
                    j == 1 || j == n)
                    document.write("*");
                else
                    document.write(" ");
            }
            document.write("\n");
        }

    }

        var rows = 8;
        print_square(rows);

Output: 

********
**    **
* *  * *
*  **  *
*  **  *
* *  * *
**    **
********

Time Complexity: O(n²), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.